<template>
  <div>姓名:<input v-model="username" type="text" /></div>
</template>

<script>
export default {
  data() {
    return {
      username: "",
    };
  },
  wath: {
    username(newVal, oldVal) {
        console.log(newVal,oldVal);
    },
  },

  mounted() {},

  methods: {},
};
</script>

<style lang="scss" scoped>
</style>